1. Field of the Invention
In general, the present invention relates to protective housings for electronic components. More specifically, the present invention relates to protective housings for electronic components that help dissipate heat produced by the electronic components.
2. Description of the Prior Art
It is well known that certain configurations of electronic components generate significant heat as a result of their operation. It is also well known that if the produced heat is not dissipated, the rise in temperature surrounding the electronic components can cause the those electronic components to fail. For this reason, many electronic components are manufactured with heat sink structures that are intended to absorb the heat produced by the electronic components and dissipate that excess heat into the surrounding environment. In many applications, the various heat sink structures are positioned near vents so that natural convection cooling occurs with the surrounding environment. In other applications, heat dissipation is assisted by a fan that forces air past the various electronic components and the heat sink structures. The passing air greatly increases convection, thereby adding to the rate at which the electronic components are cooled.
Often electronic components are placed in environments that are exposed to the elements. For example, electronic components are often suspended along telephone lines and on the exterior of buildings. In such applications the electronic components must be hermetically sealed and isolated from the surrounding environment. If the electronic components are not isolated from the surrounding environment, mist, due, rain, dust and other contaminants could contact the electronic components and cause those components to fail.
Since the electronic components must be isolated from the surrounding environment, traditional cooling schemes that uses external air to directly cool the electronic components can not be used. Rather, in the prior art, electronic components that must be cooled are often placed within a protective housing. The protective housing isolates the electronic components from the surrounding environment. Furthermore, the protective housing itself is used as a heat sink structure wherein the structure of the housing absorbs heat from the electronic components and the housing surrenders heat to the surrounding environment by convection.
Prior art protective housings are exemplified by U.S. Pat. No. 4,535,386 to Frey et al., entitled NATURAL CONVECTION COOLING SYSTEM FOR ELECTRONIC COMPONENTS and U.S. Pat. No. 4,259,843 to Kausch, entitled ISOLATION CHAMBER FOR ELECTRONIC DEVICES. A problem associated with prior art protective housings is that the protective housing tends to absorb heat from the electronic components and loose heat to the surrounding environment with a relatively low efficiency. As a result, the amount of heat capable of being dissipated is relatively small, thereby limiting the types of electronic components that can be placed in a housing of a certain size. Furthermore, since the heat exchange efficiency of such prior art protective housings is relatively small, the protective housing must often be much larger than is needed to surround the electronic components in order to provide enough surface area for proper heat exchange rates.
A need therefore exists in the art for a protective housing for electronic components that has a high heat dissipation efficiency and need not be much larger that the electronic components that the housing protects.